1. Technical Field
The present invention relates to a Lentinula edodes strain. More particularly, the present invention relates to a novel strain of shiitake mushrooms [Lentinula edodes (Berk.) Pegler] with new morphology and taste, identified as Lentinula edodes GNA01 (Accession No.: KCCM11135P), and a fruit body obtained by culturing the stain.
2. Description of the Related Art
Shiitake mushrooms (also called as pyogo, binomial name: Lentinula edodes (Berk.) Pegler), belonging to the Lentinula genus of the Marasmiaceae family, were first introduced into the academic world by the English botanist Berkeley after he collected them in Japan. Shiitake mushrooms are native to Korea, China, and Japan. In Korea, shiitake mushrooms are given various names, for example, hyangsim, mago, and oak tree mushroom, and are known as a member of the three famous edible mushrooms inclusive of pine mushrooms and Sarcodon aspratus. 
Shiitake mushrooms bud and grow on dead bodies or branches of broadleaf trees such as oak trees (e.g., acorn trees, Mongolian oak, Korean oak), red-Leaved Hornbeam, chestnut trees, etc., from the spring to the fall, but can now be artificially cultivated. Unlike other mushrooms, shiitake mushrooms are grown at moderate temperatures (optimal 22˜28° C., up to 32° C.).
Shiitake mushrooms generally produce extensive mycelia with clamp connections. This fungal species is dioecious with tetrapolarity. When the spores of the mushrooms germinate, they produce hyphae, called monokaryons, with a single nucleus in each compartment. At some stage in their growth, two monokaryons of different compatibility groups fuse to form a dikaryon (hybrid strain). The dikaryon is brown-colored and hardens under light, developing into a fruit body. The hyphal growth of shiitake mushrooms, although slower than that of oyster mushrooms, occurs well in oak tree logs.
The fruit body, as shown in FIGS. 1 and 2, is hemiangiocarpous and has a stipe connected to the center of a pileus from which lamellae spread. The pileus is pale or dark brown, while both the stipe and the lamellae are white. The pileus is round with a various diameter range including less than to 3 cm and greater than 10 cm, depending on nutrients, environment and species. The pileus curls inward in the early stage of the fruit body development, but becomes flatter as the fruit body grows larger. Shiitake mushrooms have a hard fleshy body, and its characteristic scent is stronger when it is dried. The lamellae are thin and white and the stipe is white or brownish while being toughly fibrous.
In the 1970s, lentinan, a β-D-glucan derived from shiitake mushrooms, was found to have anticancer activity. Since then, pharmaceutical activity of shiitake mushroom has been studied (Chihara et al., 1970; Tamura et al., 1997). Among nutrients found in shiitake mushrooms are crude proteins, glycolipids, ash, carbohydrates, fiber, and amino acids. In recent years, shiitake mushrooms have been processed into various foods, snacks, fermented milk drinks, soups, etc. (Ryu, 1998), and actively studied for physiologically active ingredients having anti-inflammation, anti-hypertension, and antithrombosis effects (Ohnuma et al., 2000, Yaoita et al., 1998, 1999).
However, shiitake mushrooms, unlike other mushrooms, have a single crop period of as long as 4˜5 years, and high expense is required for studies on of the breeding of shiitake mushrooms. Under these circumstances, studies for developing variants of shiitake mushrooms have mainly been undertaken by the Forest Mushroom Research Center under the support of the National Forestry Cooperative Federation, and by the Korea Forest Research Institute in Korea.
Only an extremely limited number of Korean variants of shiitake mushroom have been bred, and none of them are better in general properties than Japanese variants. There is a need for new variants of shiitake mushrooms. Because the International Convention for the Protection of New Varieties of Plants according to the Union Internationale Pour la Protection des Obtentions Vegetales (UPOV) has been applied to shitake mushroom since 2008, a royalty must be paid on the use of Japanese or Chinese variants.
Therefore, there is a pressing need for developing a novel variant of shiitake mushrooms that is superior to conventional variants including Japanese and Chinese mushrooms in terms of general properties.